1. Technical Field
The present invention relates to an analysis device.
2. Related Art
As methods for measuring various substances contained in biological samples such as blood, for example, methods with enzyme sensors using enzymes are known. In an enzyme sensor utilizing an electrochemical reaction system in which a general enzyme is used, a signal is obtained by detecting, on an electrode surface, a transfer of electrons generated based on an enzymatic catalytic reaction. Even when a colorimetric reaction system, which depends on changes in the optical properties of a pigment, is used as a detection method, its basic reaction is derived from the enzymatic catalytic reaction (oxidation-reduction) and involves electron transfer. In these reaction systems, electron transport efficiency in the reaction systems influences detection sensitivities. Various techniques in which the electron transport efficiency is improved in order to increase the sensitivity of enzyme sensors are known.
For example, National phase publication (Translation of PCT Application) No. 2002-514305 discloses a sensor in which a surface of an electrode is modified with a substance having a helical structure, such as nucleic acid, as a conductive polymer, to promote electron transfer to or from an enzyme molecule to be targeted.
Since electron transfer between an electrode and an enzyme occurs through the active center of the enzyme, the manner of the arrangement of a site, in which the active center is present, with respect to the electrode is important. In order to decrease influences on the orientation of the active center of an enzyme and therefore to transport electrons efficiently, molecules which function like an electron transport mediator which is oxidized/reduced to transport electrons, for example, complexes having, as an active center, a transition metal such as iron, copper, osmium, or ruthenium, are known, and sensors using such a complex are also known (for example, see Japanese National phase publication (Translation of PCT Application) Nos. 2006-509837 and 2005-520172).
As an enzyme electrode, a system in which a polypyrrole is used is known (for example, Biosensors & Bioelectronics, Vol. 7, (1992) pp. 461-471 and Sensors and Actuators B, Vol. 106, (2005) pp. 289-295). Since pyrrole, which is a monomer, has poor water-solubility, it is not possible to directly mix pyrrole with an enzyme liquid to prepare an enzyme electrode on the surface of an electrode material. Therefore, for example, in these documents (i.e., Biosensors & Bioelectronics, Vol. 7, (1992) pp. 461-471 and Sensors and Actuators B, Vol. 106, (2005) pp. 289-295), a polymerization reaction is carried out using ferric chloride and a pyrrole solution in a track etched membrane and, thereafter, the membrane is impregnated with an enzyme liquid to obtain an electrode.